Basic Information from Blizzard regarding Druids:
Druids are the keepers of the world. Locked in slumber for generations, they awoke to meet the threat of the Burning Legion during its recent invasion. After Archimonde's defeat, the Druids chose to remain in the waking world and help to rebuild their shattered lands. The Legion's attack left a terrible scar on the natural order, and the Druids seek to heal it.
The Druid gives players several play style options. The Druid in normal form is a caster that can fight with spells or via melee combat. In Bear Form the Druid becomes a Warrior with Rage. While in Cat form the Druid becomes a Rogue with Energy and stealth. The Druid can also transform into two other special animal forms. The Druid can also take on the role of a Priest, casting spells to heal itself and fellow characters. A Druid is not as versatile in their abilities as a Priest is, lacking the spells Holy Word: Shield and Resurrection, but is otherwise a very capable healer.
Valid Races: Night Elf, Tauren
The TenTonHammer take on Druids
The Druid is an interesting class that can use a form of lycanthropy to change shapes into different animals to suit different situations. The Druid is able to cast a variety of supportive and offensive spells that can assist a party when needed. Druidic magic can vary; from the offensive "Thorns" to the curative "Healing Touch", a Druid can make itself useful in almost any situation.
Links to information on other WoW sites
Blizzard WoW site - The official Blizzard WoW Druid information page.
Druid Articles - Article submissions from players about Druids on "The Knights who say... Ni!" site.
Druid Character guide - Starting levels and brief talent descriptions at the
wowvault.ign.com site.
The Druids Grovet - A site devoted to the Druid class in multiple MMORPGs.
Druids of the Wood - An entire site devoted to the Druid class.